Solve this Simple Riddle!

i got a simple riddle for you all. the one with best answer will be mark with best response. it just a simple riddle that even a child can answer it. here :
" A traveler met up with an adult and a child. he stopped and them for some water to drink. then after quenching his thirst,the traveler ask them :
"Is this your child?",yes
and then he ask the child "Is this your father?"
the child answered. "No"
what the relationship between the two of them?

You met a child and his mother,.Not to complain but please ask questions or have discussions that require an answer more that a sentence long. I know I am not in this for the money but some are and as long as you ask questions like this you will get very few if any answers, I am only telling you this because I couldn't understand why I was not getting any responses to my simple questions. Just my opinion, and feel free to accept or not.